To be certain about things is reassuring. It allows feelings of safety, security.
For knowledge, for understanding the world, humankind seems to have turned at first to what could be inferred from the spirits of things — the spirits associated with or inherent in everything: in mountains, in trees, in bodies of water. The spirits could be understood, at least partly, because they were similar to people in having emotions and desires.
Eventually — quite recently, only a few thousand years ago — the plurality and hierarchies of spirits and gods yielded to monotheistic religions in most parts of the world. Even more recently, and only in the most powerfully developed countries, religion yielded to science.
That is to say, traditional religion yielded to scientism, the religion of science. Even the monotheistic gods have emotions and desires, but science doesn’t. So knowledge became entirely impersonal, at least in principle.
Nowadays, then, for real certainty we look to science. “Scientific” stands for unquestionably true. Science is the gatekeeper of truth. “Science” and “scientific” are mediators of being certain, being sure about something.
Consequently, a great deal of arguing to-and-fro has to do with whether something is scientific:
Does it emerge from use of the scientific method?
Is it reproducible?
Is it falsifiable?
And if a claim doesn’t satisfy those criteria or equivalent ones then it’s dismissed as not scientific, or as pseudo-science, or as just plain not to be believed.
That’s an indirect way of judging believability, and arguments about whether something is scientific can be and have been highly abstract, complicated, and sophisticated as technical philosophical discourse tends to be.
Instead, why not go directly at the issues of certainty and truth and just ask, what does it take to be justifiably and reliably certain about something?
In any case, although we use science as mediator of certain truth, we’ve also learned that contemporary scientific knowledge and understanding really isn’t always reliably true. Even when an explanation has been based on tangible evidence, and withstood challenges and tests — if it’s properly scientific, in other words — we’ve learned that it may be misleading. Scientific progress with periodic scientific revolutions has continually revealed flaws, deficiencies, errors, in what were for a time the most widely and fully accepted scientific theories.
If something has always happened in the past, can we be certain that it always will happen in the future? We’ve learned that we cannot be quite certain.
When an explanation has always worked in the past, can we be certain that it always will work in the future? We’ve learned that we cannot be quite certain.
When tangible things are sub-divided into their ultimate components, those turned out to be nothing like objects accessible to direct human observation. They do not fit our concepts of particles or energy, although many of their reactions can be calculated using sometimes particle equations and sometimes wave equations. They behave sometimes as though they were locatable, delimited in space-time, and at other times appear to be “non-local”, not so delimited.
In other words, we’ve learned that we cannot get certain and humanly comprehensible understanding of everything about the whole of the natural world. It’s surely time to accept that, that human beings will never attain complete certainty.
That could be liberating. It would make more feasible pragmatic, non-ideological communication and cooperative action — if only we could be rid of the ideologues: the true believers in a religion, including the true believers in scientism, the religion of science. Anyone who claims complete certainty has insufficient warrant for that claim. The world and its behaviors can be known only within degrees of probability. Instead of arguing about whether something is scientific or whether it is true, we ought to be discussing plausibility, likelihood, utility, risk.
Instead of dismissing as pseudo-science the claims that Loch Ness Monsters are real animals, we should be content to say, “Feel free to believe that if the evidence seems to you sufficiently convincing. For my part, I’ll wait until someone shows me an actual specimen or an indubitable bit of one”. And similarly with yetis and other cryptids, and with UFOs, and with all other anomalous or Fortean reports or claims.
Instead of arguing over being for or against vaccination, we should ask for the statistical data of harm possibly caused by each specific vaccine. For instance, since in many countries the chance of becoming infected by polio is less than the risk of contracting polio from the oral vaccine. perhaps official sources might be less dogmatic about enforcing use of that particular vaccine (“Polio vaccines now the #1 cause of polio paralysis”; “Oral polio vaccine-associated paralysis in a child despite previous immunization with inactivated virus”; “Bill Gates’ polio vaccine program caused 47,500 cases of paralysis death“).
And so on. For every drug and every treatment, we should demand that the Food and Drug Administration require data on NNT and NNH — NNT: the number of patients needed to be treated in order that 1 patient benefit, compared with NNH: the number of patients who must receive a drug in order to have 1 patient experience harm [How (not) to measure the efficacy of drugs]. That would go a long way to decreasing the number of people nowadays being killed by prescription drugs, which are the 3rd or 4th leading cause of death in First-World countries (Peter C. Gøtzsche, Deadly Medicines and Organised Crime: How Big Pharma Has Corrupted
Healthcare [Radcliffe, 2013]; David Healy, Pharmageddon [University of California Press, 2012]).
We need more data and less dogmatism.